Waste Water Engineering Online Test – Multiple Choice Questions and Answers

1. If the depletion of oxygen is found to be 2.5 mg/litre after incubating 2.5 ml of sewage diluted to 250 ml for 5 days at 20°C, B.O.D. of the sewage is

2. For providing an Indian type W.C., the R.C.C. slabs in the toilet portion

3. The digested sludge from septic tanks, is removed after a maximum period of

4. The detention period for plain sedimentation water tanks, is usually

5. A manhole is classified as shallow if its depth is between

6. The standard B.O.D. of water is taken for

7. To prevent settling down of sewage both at the bottom and on the sides of a large sewer, self-cleaning velocity recommended for Indian conditions, is

8. A drop manhole is provided if

9. Rate of flow of sewage is generally assumed

10. The amount of oxygen consumed by the aerobic bacterias which cause the aerobic biological decomposition of sewage, is known